1. Field of the Invention
Embodiments of the invention relate to a permanently or temporarily implantable device having a longitudinally extended electrical conductor.
2. Description of the Related Art
Such devices, for example, electrode conductors for electrical stimulation or catheters with electrodes, have the disadvantage that the electrical leads thereof can heat up in an MRI machine because the alternating magnetic fields in an MRI machine induce electrical currents in the electrical conductor which are not insignificant. For this reason, patients with heart pacemakers usually cannot be examined in an MRI machine using today's technology or can be examined only to a limited extent.
Implantable heart pacemakers or defibrillators typically have at least one stimulation electrode lead attached to said pacemaker, wherein said electrode lead has a standardized electrical connection at its proximal end, said end being provided for connection to the heart pacemaker or defibrillator and said electrode lead having one or more electrode poles on its distal end, said distal end being provided for locating the same in the heart. Such an electrode pole serves to deliver electrical pulses to the (myocardial) tissue of the heart or to sense electrical fields, in order to be able to sense an activity of the heart as part of so-called sensing. To this end, electrode poles typically form electrically conductive surface sections of an electrode lead. Electrode poles are typically provided as ring electrodes in the form of a ring around the electrode lead or in the form of a point or tip electrode at the distal end of the electrode lead. The electrode poles are electrically connected to contacts of the electrical connection of the electrode lead at its proximal end via one or more electrical conductors. Thus, one or more electrical conductors run between the contacts of the electrical connection of the electrode leads at their proximal end and the electrode poles at the distal end of the electrode lead, electrically connecting one or more of the electrode poles to one or more of the contacts. These electrical conductors may in turn be used for transmitting stimulation pulses to the electrode poles and to transmit electrical signals picked up by the electrode poles to the proximal end of the electrode lead and are also referred to as functional leads in the course of the further description. Such functional leads are electrical conductors, which are necessary for the function of the respective electrode lead and as such are exposed to the risk that electrical currents are induced in them due to external alternating magnetic fields. This electrical current may, for instance, result in unwanted heating of the functional leads or of the electrode poles connected to them or may result in a discharge of corresponding currents via the electrode poles into the surrounding tissue, thereby heating the surrounding tissue.